I appreciate the comments on the last few posts. I wanted to point out a recent study which shows how gut bacteria can affect weight in the long run. In this study (free full text), researchers measured bacteria in children at 6 and 12 months, and then checked on their weight status years later.
As it turns out, differences in gut bacteria in the first year of life predicted their weight status later on. The children with less "good" bacteria were more likely to be overweight. Here's a table from the paper:
TABLE 2. Bacterial counts in fecal samples analyzed by fluorescent in situ hybridization during infancy
Normal-weight children
Overweight children
Mann-Whitney U test
Bifidobacteria ( x 10 9 cells/g)
6 mo
2.47 (1.52–4.21) [16] 1
1.46 (0.35–2.35) [23]
12 mo
0.70 (0.39–1.69) [19]
0.20 (0.14–0.88) [22]
During infancy 2
1.62 (1.01–3.73) [14]
1.05 (0.61–1.38) [20]
0.08
Bacteroides ( x 10 8 cells/g)
6 mo
0.62 (0.12–3.05) [16]
0.83 (0.24–2.28) [23]
12 mo
0.43 (0.13–2.50) [19]
0.91 (0.39–4.45) [22]
During infancy 2
0.96 (0.24–4.0) [14]
1.26 (0.49–2.77) [20]
0.44
Lactobacilli ( x 10 8 cells/g)
6 mo
3.26 (0.57–8.25) [16]
1.14 (0.60–2.54) [23]
12 mo
1.20 (0.64–2.30) [19]
1.13 (0.26–2.76) [22]
During infancy 2
2.46 (1.24–4.59) [14]
1.43 (0.82–2.23) [20]
0.11
Clostridia ( x 10 8 cells/g)
6 mo
0.91 (0.38–3.63) [16]
0.73 (0.24–1.78) [23]
12 mo
1.48 (0.44–5.87) [19]
0.45 (0.065–2.78) [22]
During infancy 2
2.18 (1.18–3.74) [14]
1.49 (0.39–2.45) [20]
0.15
Total cell count ( x 10 9 cells/g)
6 mo
5.47 (3.43–10.10) [16]
3.52 (2.26–5.09) [23]
12 mo
3.44 (2.07–10.35) [19]
3.22 (1.96–5.03) [22]
During infancy 2
4.44 (2.68–9.39) [14]
3.54 (2.27–5.11) [20]
0.29
You can see that the normal weight children all started with more of these different types of bacteria than the overweight children. The authors feel this is significant and make a few related statements:
" We show here for the first time in the human situation that differences in the intestinal microbiota may precede overweight development. ... Thus, these findings unequivocally imply that high numbers of bifidobacteria and low numbers of S. aureus in infancy may provide protection against overweight and obesity development."
You might think that this could be explained by breastfeeding (which delivers good bacteria), but that's not the case. The normal weight children were only breastfed about a month longer than the overweight children - not really enough to make a difference.
I feel this is a pretty substantial study. In addition, I have a few other related posts that I will put up soon.
I appreciate the comments on the last few posts. I wanted to point out a recent study which shows how gut bacteria can affect weight in the long run. In this study (free full text), researchers measured bacteria in children at 6 and 12 months, and then checked on their weight status years later.
As it turns out, differences in gut bacteria in the first year of life predicted their weight status later on. The children with less "good" bacteria were more likely to be overweight. Here's a table from the paper:
TABLE 2. Bacterial counts in fecal samples analyzed by fluorescent in situ hybridization during infancy
You can see that the normal weight children all started with more of these different types of bacteria than the overweight children. The authors feel this is significant and make a few related statements:
" We show here for the first time in the human situation that differences in the intestinal microbiota may precede overweight development. ... Thus, these findings unequivocally imply that high numbers of bifidobacteria and low numbers of S. aureus in infancy may provide protection against overweight and obesity development."
You might think that this could be explained by breastfeeding (which delivers good bacteria), but that's not the case. The normal weight children were only breastfed about a month longer than the overweight children - not really enough to make a difference.
I feel this is a pretty substantial study. In addition, I have a few other related posts that I will put up soon.